Restoration Theory Flashcards
(40 cards)
Generally, what is the restoration theory about?
Sleep being a period of rejuvenation and repair
Why is sleep thought to be a period of rejuvenation and repair?
Important biological functions take place, restoring biological system to a better working order
What are the 2 slightly different versions of restoration theory?
1) Oswald (1980)
2) Horne (1988)
Outline the different functions of different types of sleep according to Oswald (1980)
SWS in body repair
REM in brain recovery
Summarise Oswald (1980)
Sleep helps to reverse or restore biochemical and physiological processes that are progressively degraded during the day
How do we know about the different functions of different types of sleep?
SWS - increased growth hormone production during the 4 stages which indicate bodily restoration and repair
REM - high levels of brain activity during REM indicates brain restoration
Why is the production of growth hormones during SWS important?
Particularly important during childhood, and also important in adulthood as proteins are fragile and constantly need to be renewed
When is growth hormone released?
It is released in pulses during the day but more at night
Name 2 research studies which support the idea that SWS is associated with the production of growth hormone?
1) Sassin (1969)
2) Krueger (1985)
Outline Sassin (1969)
Found that when sleep waking cycles reversed (i.e. sleep in the morning) the release of growth hormone is also reversed showing that growth hormone release is controlled by neural mechanisms relating to SWS
Explain one bit of evidence supporting the idea that SWS is associated with the production of growth hormone
The amount of growth hormone released correlates with the amount of SWS and the decline in growth hormone in older age has been associated with reduced SWS
Outline Krueger (1985)
Lack of SWS is associated with reduced functioning of the immune system as antibodies (proteins) are regenerated during cell growth and protein synthesis in SWS
Explain one bit of evidence supporting the idea that REM is associated with brain recovery
The % of active/REM is a lot higher in babies than adults and even higher in premature babies as they need rapid brain growth - it has been suggested that the amount of REM is proportional to the immaturity of the offspring at birth
Name 3 research studies supporting the association of brain recovery with REM
1) Siegel (2003)
2) Siegel & Rogawski (1988)
3) Crick & Mitchison (1983)
Outline Siegel (2003)
Platypus are immature at birth and have 8 hours of REM whereas a dolphin can swim at birth and has almost no REM, suggesting a relationship between neural development and REM
Outline Siegel & Rogawski (1988)
Suggest REM allows a break in neurotransmitter release which in turn permits neurons to regain sensitivity and body function properly - support from MAOIs which are drugs that increase neurotransmitters with the side effect of abolishing REM completely suggesting increased monomines means monomine receptors don’t have to be revitalised and so no need for REM
Outline Crick & Mitchison (1983)
Proposed in REM, unwanted memories are discarded making more important memories accessible but recent, more complex relationship - REM procedural memory whereas SWS for semantic & episodic memory
Name 7 bits of evidence for Oswald (1980)
1) Sassin (1969)
2) Krueger (1985)
3) GH correlating with amount SWS & old age
4) % REM in babies
5) Siegel (2003)
6) Siegel & Rogawski (1988)
7) Crick & Mitchison (1983)
What are 3 positive evaluative points for Oswald (1980)?
1) If sleep has a restorative effect, then sleep deprivation should have clear consequences - Rechtschaffen (1983)
2) REM rebound - Empson (2002)
3) The effect of increased physical exercise - Shapiro (1981)
Outline Rechtschaffen (1983)
Forced rats to remain physically active by rotating a disc they were on every time they started to go to sleep, After 33 days, all sleep-deprived rats died
What does Rechtschaffen (1983) show?
That sleep is necessary for life and thus suggests that sleep has a restorative effect
What are 4 negative points about Rechtschaffen (1983)?
1) Possible that stress direct cause of death
2) Ethical issues
3) Generalisability
4) Rattenborg (2005) similar experiment with pigeons who suffered no ill effects suggesting it is different across species
Explain the REM rebound in relation to Oswald (1980)
Sleep deprivation may lead to REM rebound - Empson (2002) woke ppts when eyes started to dart about (REM) and found increased tendency into REM when back to sleep and on recovery nights, proportion spent in REM increased with rebound being as much as 50% higher than normal
Explain the effect of physical exercise in relation to Oswald (1980)
Increased physical exercise should lead to increased sleep in order to restore proteins and biochemical used - Shapiro (1981) found long-distance athletes after 56 mile race, slept an hour longer for 2 nights with increased SWS suggesting does aid restoration and NREM associated more with physical recovery